1 files changed, 11 insertions, 11 deletions

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 123f3f297284..a97505b78671 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -108,7 +108,6 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 			mp_opt->suboptions |= OPTION_MPTCP_DSS;
 			mp_opt->use_map = 1;
 			mp_opt->mpc_map = 1;
-			mp_opt->use_ack = 0;
 			mp_opt->data_len = get_unaligned_be16(ptr);
 			ptr += 2;
 		}
@@ -157,11 +156,6 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		pr_debug("DSS\n");
 		ptr++;
 
-		/* we must clear 'mpc_map' be able to detect MP_CAPABLE
-		 * map vs DSS map in mptcp_incoming_options(), and reconstruct
-		 * map info accordingly
-		 */
-		mp_opt->mpc_map = 0;
 		flags = (*ptr++) & MPTCP_DSS_FLAG_MASK;
 		mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0;
 		mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0;
@@ -369,8 +363,11 @@ void mptcp_get_options(const struct sk_buff *skb,
 	const unsigned char *ptr;
 	int length;
 
-	/* initialize option status */
-	mp_opt->suboptions = 0;
+	/* Ensure that casting the whole status to u32 is efficient and safe */
+	BUILD_BUG_ON(sizeof_field(struct mptcp_options_received, status) != sizeof(u32));
+	BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct mptcp_options_received, status),
+				 sizeof(u32)));
+	*(u32 *)&mp_opt->status = 0;
 
 	length = (th->doff * 4) - sizeof(struct tcphdr);
 	ptr = (const unsigned char *)(th + 1);
@@ -654,6 +651,7 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 	bool drop_other_suboptions = false;
 	unsigned int opt_size = *size;
+	struct mptcp_addr_info addr;
 	bool echo;
 	int len;
 
@@ -662,7 +660,7 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *
 	 */
 	if (!mptcp_pm_should_add_signal(msk) ||
 	    (opts->suboptions & (OPTION_MPTCP_MPJ_ACK | OPTION_MPTCP_MPC_ACK)) ||
-	    !mptcp_pm_add_addr_signal(msk, skb, opt_size, remaining, &opts->addr,
+	    !mptcp_pm_add_addr_signal(msk, skb, opt_size, remaining, &addr,
 		    &echo, &drop_other_suboptions))
 		return false;
 
@@ -675,7 +673,7 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *
 	else if (opts->suboptions & OPTION_MPTCP_DSS)
 		return false;
 
-	len = mptcp_add_addr_len(opts->addr.family, echo, !!opts->addr.port);
+	len = mptcp_add_addr_len(addr.family, echo, !!addr.port);
 	if (remaining < len)
 		return false;
 
@@ -692,6 +690,7 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *
 		opts->ahmac = 0;
 		*size -= opt_size;
 	}
+	opts->addr = addr;
 	opts->suboptions |= OPTION_MPTCP_ADD_ADDR;
 	if (!echo) {
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDRTX);
@@ -980,8 +979,9 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
 		if (subflow->mp_join)
 			goto reset;
 		subflow->mp_capable = 0;
+		if (!mptcp_try_fallback(ssk))
+			goto reset;
 		pr_fallback(msk);
-		mptcp_do_fallback(ssk);
 		return false;
 	}